Got to go with Pym or Ultron. Ultron created the Vision, who is so awesome he knew Ultron was evil and turned good. Pym, however, created Ultron, so I guess he in turn did kind of create the Vision. Gotta give it to Ant-Man.

Much as I like DC, I have to go with Hank Pym on this one. When you look at the sheer scale of trouble that Ultron has caused over the years, its hard to compare. Yeah, Amazo has the combined powers of the entire Justice League, but he's generally beaten within one or two issues. Plus, Amazo can be shut down just by disbanding the League. Ultron is so powerful and so evil, he can't help but accidentally create successors who turn good.

Madison is a mutant technoformer able to psionically rearrange metal, plastic and glass into any form he can think of. He can manipulate items on an atomic level and can create highly complex machines, weapons, vehicles, and other items, and he is particularly skilled at psionically restructuring machinery into duplicating the form and functions of parts of the human body. He also seems to have a talent for design similar to that of Forge. It has been remarked by telepaths that his mind seems more like a machine than man

Madison is a mutant technoformer able to psionically rearrange metal, plastic and glass into any form he can think of. He can manipulate items on an atomic level and can create highly complex machines, weapons, vehicles, and other items, and he is particularly skilled at psionically restructuring machinery into duplicating the f and thanksorm and functions of parts of the human body. He also seems to have a talent for design similar to that of Forge. It has been remarked by telepaths that his mind seems more like a machine than man

No love for Phineas T. Horton? Dude created a kickass superhero android who could pass for human, and did it in the 1930s. I wonder whether any of these guys could have created the equal of the original Human Torch with '30s technology.